- #1
Mogarrr
- 120
- 6
I'm trying a few elementary counting problems, and a few are proving very difficult (for me). I have the answers and explanations, which I understand, so that's not the problem. I don't want to memorize answers. The problem is systematically analyzing these problems. My intuition is almost always wrong with counting, so I don't want to rely on any intutive explanations (adding to my frustration, most explanations use the intuitive approach). Here are some problems I found troubling:
My telephone rings 12 times each week, the calls being randomly distributed among the 7 days. What is the probability that I get at least one call each day?
If n balls are placed at random into n cells, find the probability that exactly one cell remains empty
A closet contains n pairs of shoes. If 2r shoes are chosen at random (2r<n), what is the probability that there will be no matching pair in the sample?
Given problems like these, how do you systematically work through the problem.
My telephone rings 12 times each week, the calls being randomly distributed among the 7 days. What is the probability that I get at least one call each day?
If n balls are placed at random into n cells, find the probability that exactly one cell remains empty
A closet contains n pairs of shoes. If 2r shoes are chosen at random (2r<n), what is the probability that there will be no matching pair in the sample?
Given problems like these, how do you systematically work through the problem.